Which statement about the overload bit in IS-IS is true?
A.
The IS-IS adjacencies on the links for which the overload bit is set are brought down.
B.
Routers running SPF ignore LSPs with the overload bit set and hence avoid blackholing traffic.
C.
A router setting the overload bit becomes unreachable to all other routers in the IS-IS area.
D.
The overload bit in IS-IS is used only for external prefixes.